2005 Suzuki 140 4 Stroke Compression Test

[UncleBlack]

What is the compression supposed to be on a 2005 Suzuki 140 4 Stroke with 75 hours and how should the test be preformed?

 

[rodbolt]

Re: 2005 Suzuki 140 4 Stroke Compression Test

compression test on that engine is a teat on a boar hog.
have a leakdown test run.
its far more accurate and faster than a compression test.

 

[BOAT DOCTOR]

Re: 2005 Suzuki 140 4 Stroke Compression Test

warm the motor up then pull the spark plug use the warm up lever and put it all the way up then check compression i seen them rangr from 180 all the up to 210 psi you want all 4 cyclinders to close to the same no more than a 15% difference

 

[rodbolt]

Re: 2005 Suzuki 140 4 Stroke Compression Test

see why I say a compression test on small 4 strokes is a teat on a boar hog?
a leakdown test is faster and far more indicative of cylinder sealing ability.

 

[UncleBlack]

Re: 2005 Suzuki 140 4 Stroke Compression Test

THX. I found a Suzuki mechanic yesterday, who showed me the shop manual.
1. Warm up engine.
2. Remove throttle linkage and place the throttle body leaver in full open position.
3. Specks: 185 psi to 242 psi with a 14 psi delta maximum between all cylinders.

 

[rodbolt]

Re: 2005 Suzuki 140 4 Stroke Compression Test

dunno
I dont run compression tests on 4 stroke outboards.
I only use leak down tests as the accuracy and speed is so much greater.
by the time you disable the spark and fuel controls,sometimes its as simplle as pulling the stop lanyard, installing the tester,cranking it over, and if by yourself either rigging a remote or craling in and out, I can whip the engine to #1 TDC, either 1 or 4 is on compression stroke, do my test on whichever one is on compression stroke then simply rotate the crank 180* and hit the next cyl in the firing order.
if all cylinders are less than 15% leakage all are good, if one is bad then its easy,while the tester is still hooked up, to determine is it rings,ex valves or intake valves.
if you suspect a head gasket then tape over the idle relief ports,submerge the gearcase and look for bubbles out of the water pump drain hole.
so you do a compression test, its still under warrenty, it fails. you call the service rep.
first thing the rep is gonna say is do a leakon test.

 

[reeldutch]

Re: 2005 Suzuki 140 4 Stroke Compression Test

We winterize a lot of four strokes and we always do a compression check.
i disagree with rotbold on this one.
2 stroke or 4 stroke.
we register the numbers and compare them with the last time we looked at the motor.
a good decarb (cleaning the exhaust valves) could make the difference and seen in a compression test.
specially have a lot of succes this way on yamaha jet skis.

just to let you know it is just like checking your pulse .
if there is a problem you will still might have to do a leak leakdown to find a real problem.
but for general maintenence and keeping your eyes on it its a good thing to do.

 

[99yam40]

Re: 2005 Suzuki 140 4 Stroke Compression Test

But like Rod said, if it is easier and faster to do the leak down test and gives more info as to what any problem could be, intake valves, exhaust valves, rings. Why would you waist time on a compression test unless you do not have the equipment, especially if you see a problem and then have to do the leak down test anyway.

 

[rodbolt]

Re: 2005 Suzuki 140 4 Stroke Compression Test

i need to post a pic of the dry stack area and of maybe 450 4 strokes we deal with.
on the 4 stroke outboard,especially if your by yourself and the boat is on a work rack outside and only accessible with a ladder, I remove the plugs and flywheel cover.
on an inline 4 four stroke from there I can be done with the leak down in less than 4 min, can record the numbers for reference and rotate the crank a max of 5 times,including the rotation to line up either the #1and4 TDC or the #2,3 TDC.
its faster, more accurate, does not rely on battery conditon and its what the factory reccomends.
anything over 15% means there is an issue that needs to be addressed.
you will NEVER find ring gap lineup with a commpression test, simply WONT happen.
and ring gaps will line up on 4 stroke outboards.
so while your fumbling with batterys,climbing in and out of the boat, messing with remote starters and pulling kill lanyards, I am done and on to the next money making project.
that and I have a much more accurate picture of the cylinders ability to seal.

 

[reeldutch]

Re: 2005 Suzuki 140 4 Stroke Compression Test

And were do you get your compressed air from?
isnt that a pain in the *** to drag hoses around the yard or up a rack?
a 5 gallon remote tank pumped up with air that you have to refill every other boat saves you time?
i just cant see how it can be faster.

 

[rodbolt]

Re: 2005 Suzuki 140 4 Stroke Compression Test

I have the forklift driver move the hull on a rack near the shop.
from there we have over 200ft of airline.
simply adjust the regulator to the set point and the % gauge to the 0 point and do it.
no pain at all and is WAY more accurate.
same as if the batteries are dead.
but dead batteries wont stop a leakdown test and if the leakage is greater than 15% NO further action is nessasary other than to find and correct the excessive leakage from that cylinder.
no sense in tuning up an engine that cant seal.
reeldutch, try practicing a bit with the leakdown tester, you will find it invaluable on 4 strokes.
2 strokes are a bit more difficult as typically the TDC is a bit more touchy and its hard to keep the piston at TDC.
that an a lot of smaller pull start 4 strokes have auto-decompression devices to take the load of of electric and manual starters that render compression tests absolutly useless.

 

[reeldutch]

Re: 2005 Suzuki 140 4 Stroke Compression Test

I do not need to practice diagnosing an 4 strk engine with a leak down tester.
we only use the leak down tester if there is need for using the leak down tester.
we use the compression tester on 90 % of all engines we work on.
its a routine.
if a customer brings his boat in for a tune up, winterization or other maintenance, we will check the compression.
if a customer brings a engine in with a problem, like water in oil or no power or smoking etc we will get the leak down tester out.
thats all.
so to tell a average boat owner that a compression test is basicly useless is just plane bull crap.

 

[rodbolt]

Re: 2005 Suzuki 140 4 Stroke Compression Test

no its not crap.

friday we found and fixed an issue.
compresison was fine about 140 on all four,2002 F115.
leak down on 2 and 3 was 5%,leakdown on 1 was 35% leakdown on 4 was 45%.
borescope showed some excessive deposits,ran 1/2 qt of yamaha yies mixed with 3 gallons of gas through it and the leakdown came back to about 5% across the board.
compression test did NOT show the rings were coking up.
leak down test DID show the rings were coking up and we were able to correct it BEFORE it took out a cyl or a piston skirt.
reason the rings are coking? the engine at WOT with 1 person onboard will only turn 5300 RPM.
its simply overpropped and EFI motors dont like that.
but a compression test wont find that issue until its to late.
its lso why I made my master tech certs the first try and our dealership has above a 90% customer satifaction rateing.
we try very hard to fix things he customer doesnt even know is going to break.
I have options, option 1 takes two people one cranking one in the back moving the compression tester, option two unplug the ign harness and use my boat in a box and monkey around with it rissking possible connector pin damage.
option 3 simply remove the plugs,place the engine at TDC for #1 and rotate the engine by hand while testing lekdown.
on a 2cyl you may have to rotate it twice,3 times for a 3cyl,5 times for a 4 cyl and 7 times for a V6.
and most small 4 strokes use an auto decompression device that renders compression testing useless.
a leakdown is simply more accurate,they actually specify numbers for it,its quick,faster than a compression test, and it only takes one person and no monkying with remote starters or boat in a box equipment.